Effect of CO2, Nd:YAG, and ArF Excimer Lasers on Dentin Morphology and Pulp Chamber Temperature: An In Vitro Study

Abstract

This study compared the effect of three laser systems: CO2 (10.600 nm), Nd:YAG (1.064 nm), and ArF excimer (193 nm) lasers on dentin hard tissue and on temperature increases of the pulp chamber. Sixty-six third molar teeth were used and randomly divided into three groups. A class I cavity was made to expose the dentin, and the pulp in the pulp chamber was removed via a hole bored in the cervical area. The pulp chamber was subsequently refilled with silicon grease, and a NiCr/NiSi thermocouple was inserted through the hole into the pulp chamber. The dentin surface was then lased for 30 s at the same settings (3 W, 2 mm spot size, 20 pps) with each laser. The average internal temperature increases were as follows: CO2, 37 degrees C; Nd: YAG, 28 degrees C; and ArF excimer, 1 degrees C. Scanning electron microscopy of the dentin in the occlusal cavity revealed extensive carbonization, isolated balls of recrystallized material, and the presence of smear layer at some dentinal tubule orifices for the CO2 and Nd:YAG lased teeth. Smear layer was also observed for the ArF excimer samples; however, they exhibited far less surface cavities than the others and seemed to undergo little morphological change on the dentin.

Ultrastructural analysis of radicular dentine surface submitted to CO2 laser at different parameters

“…Studies using SEM have demonstrated the different ultrastructural alterations of radicular dentine after CO 2 laser irradiation such as fissures and crater formation (Anic et al, 1998;Moshonov et al, 2005), exposed dentinal tubules due to the smear layer removal (Tü rkmen et al, 2000) or melting and recrystal-…”

Heat Stress Activates Interleukin-8 and the Antioxidant System via Nrf2 Pathways in Human Dental Pulp Cells

“…V arious dental treatments used in clinical practice result in an increased temperature of the tooth surface and thereby the tooth pulp (1)(2)(3)(4). Temperature changes in pulp tissue can induce inflammatory reactions and hypersensitivity, leading to pulpal necrosis requiring root canal treatment (5).…”

Anti-microbial Photo Dynamic Therapy (aPDT) in Endodontics: A Literature Review

“…Because resistance to ROS and singlet oxygen is extremely rare, hence it initiates the destruction of bacteria within the root canal system [7,9,10] .…”

“…There are concerns of some undesirable effects on surface of radicular dentin that include carbonization and cratering with some lasers types e.g. Nd:YAG and carbon dioxide lasers, and this warrants following strict protocols to minimize these effects during use of these lasers for root canal disinfection [9].…”